为了改善现有激光宽带熔覆送粉喷嘴中金属粉束发散、粉末利用率低的问题,设计了一种送粉喷嘴的准直气罩;为了实现在宽带激光束内部均匀地对熔池送粉,保证粉末受热均匀、粉束发散小,设计了一种流道.应用FLUENT软件对准直气罩内部流体分析,确定装置内部型腔和出口尺寸,以减少出口处的紊流,达到较佳的准直效果.最后利用研制的送粉装置进行送粉试验,验证了该准直气装置的实验效果.结果表明,准直气帘的宽度为粉束宽度的1.5倍时,准直效果较好.

In order to improve the situation of the metal powder radiation existing in the current powder feeding broadband laser cladding nozzles and the low utilization rate,a collimation hood of powder feeding nozzle for broadband laser cladding was designed.A flow channel was designed to realize the uniformity of inside-laser powder feeding,to ensure that the powder was heated evenly and the divergence of powder beam was small.FLUENT software was used to analyze the internal fluid of collimation gas cover,to determine the inside cavity and the outlet size of device,to reduce the turbulence at the exit and to achieve better collimation effect.The experiment of the new powder feeding device was conducted to verify the effectiveness of gas collimator device.The results indicate that the best collimation could be achieved when width of the collimated gas curtain is 1.5 times of the width of powder beam.